JP2015052796A - Display device and portable terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device that includes a louver film enabling reduction in weight and thinness.SOLUTION: A display device comprises: a light source 1; and a liquid crystal panel 4 that is provided on an observer side further than the light source 1, and the liquid crystal panel 4 comprises: two polarizers 41 and 45; a liquid crystal layer 43 that is disposed between the two polarizers 41 and 45; and a louver film 11 that includes a light transmission part 12 having trapezoid sections juxtaposed along a film surface so as to be able to transmit light, and a light absorption part 13 having the trapezoid sections juxtaposed between the light transmission parts 12 so as to be able to transmit the light. The louver film 11 is disposed on a light source side surface of the polarizer, out of the light source side further than the liquid crystal layer 43 not via a base material, and a long lower base of the trapezoid section of the light absorption part 13 and a short upper base of the trapezoid section of the light transmission part 12 are directed on the light source side.

Description

  The present invention relates to a display device including a louver film, and a mobile terminal including the display device.

  A display device such as a liquid crystal display is equipped with a video source such as a liquid crystal panel that emits a video / image to be displayed in order to solve various problems of the display device and provide a higher quality video to the observer. And an optical sheet that improves the quality of the image light from the image source and transmits it to the viewer side.

  For example, there is a problem that privacy is infringed because video light is diffused more than necessary from the display surface of the display device, so that not only the operator of the display device but also a third party can see the video. . Further, in the case of a display device arranged on a dashboard of a car such as a car navigation system, there is a problem in that an image from the display device is reflected on the front window and disturbs the driver's view. For the purpose of solving such a problem, for example, Patent Document 1 discloses a kind of optical sheet called a louver film. The louver film includes a light transmission part arranged in parallel along the film surface so that light can be transmitted, and a light absorption part arranged in parallel so as to be able to absorb light between the light transmission parts. Therefore, the film exhibits functions such as so-called peep prevention and reflection prevention, and outdoor visibility improvement. In the description of the present invention, the terms “film” and “sheet” are used without distinction.

JP 2002-303707 A

  With respect to portable terminals such as mobile phones, weight reduction and thinning are regarded as important from the viewpoint of improving portable performance, and built-in circuits and display members are also required to be lightweight and thin. However, the conventional louver film is formed on a base material, and the thickness is thick and heavy by including the base material.

  Then, this invention makes it a subject to provide the display apparatus provided with the louver film which can be reduced in weight and thickness, and the portable terminal provided with this display apparatus in view of the said problem.

  The present invention will be described below.

  Invention of Claim 1 is a display apparatus provided with the light source and the liquid crystal panel with which an observer side is provided from this light source, Comprising: A liquid crystal panel is arrange | positioned between two polarizing plates and two polarizing plates A liquid crystal layer, a light transmission part having a trapezoidal cross section arranged in parallel along the film surface so as to transmit light, and a light absorption part having a trapezoidal cross section arranged in parallel to absorb light between the light transmission parts And the louver film is disposed on the light source side surface of the polarizing plate among the light source side of the liquid crystal layer without interposing a base material, and has a long lower bottom in the trapezoidal cross section of the light absorbing portion. And a display device in which a short upper base in the trapezoidal cross section of the light transmitting portion is oriented toward the light source.

  The invention according to claim 2 is a portable terminal including the display device according to claim 1.

  ADVANTAGE OF THE INVENTION According to this invention, the display apparatus provided with the louver film which can be reduced in weight and thickness, and the portable terminal provided with this display apparatus can be provided.

It is sectional drawing which shows roughly an example of the louver film manufactured by the manufacturing method of the louver film of one example. It is the figure which expanded and showed a part of louver film shown in FIG. It is a flowchart of the manufacturing method of the louver film concerning one form. It is a conceptual diagram explaining the manufacturing method of the louver film concerning one form. It is a conceptual diagram explaining the light transmissive part formation process. It is a conceptual diagram explaining the light absorption part formation process. It is sectional drawing which shows the structure roughly about a part of display apparatus concerning one form. It is the conceptual diagram showing the example of the optical path of the light which injected into the louver film among the liquid crystal panels shown in FIG.

  Hereinafter, description will be given based on the drawings. In the drawings, for the sake of illustration and ease of understanding, the scale, vertical and horizontal dimension ratios, and the like are appropriately changed from those of the actual ones. Moreover, in each drawing, the code | symbol which becomes repeated may be abbreviate | omitted for visibility.

<Louvre film>
A louver film manufactured by a method for manufacturing a louver film according to one example will be described. FIG. 1 is a cross-sectional view schematically showing a louver film 11 which is an example of a louver film manufactured by this louver film manufacturing method. FIG. 2 is an enlarged view of a part of the louver film 11 shown in FIG.

  The louver film 11 shown in FIG. 1 and FIG. 2 can absorb light between the light transmission parts 12, 12,... Arranged in parallel along the film surface so that light can be transmitted. Are arranged in parallel with each other, and the light transmitting parts 12, 12,... And the light absorbing parts 13, 13,... Have the cross section shown in FIG. It has a shape that extends to the near side. The louver film 11 includes the light transmitting parts 12, 12,... And the light absorbing parts 13, 13,... To control the optical path of the image light incident from the light source side when provided in the display device. In addition, it can have a function of appropriately absorbing stray light and external light. The function of the louver film 11 will be described later.

  The light transmitting portions 12, 12,... Are elements having a function of transmitting image light, and are elements having a substantially trapezoidal cross section in the cross sections shown in FIGS. An upper base and a lower base longer than the upper base in the substantially trapezoidal cross section are arranged in a direction along the film surface of the louver film 11. Further, the light transmission parts 12, 12,... Have a refractive index of Np and have light transmission properties. Such a light transmission part 12, 12, ... can be comprised by hardening the light transmission part structure composition demonstrated below. The value of the refractive index Np is not particularly limited, but is preferably 1.49 to 1.56 from the viewpoint of the availability of the applied material.

  The light transmissive part constituting composition is preferably one that can be cured by light such as ultraviolet rays. For example, the following photocurable prepolymer (P1), reactive diluent monomer (M1), and photopolymerization initiator (S1) A photocurable resin composition containing the above is preferably used.

  Examples of the photocurable prepolymer (P1) include epoxy acrylate-based, urethane acrylate-based, polyether acrylate-based, polyester acrylate-based, and polythiol-based prepolymers.

  Examples of the reactive dilution monomer (M1) include vinyl pyrrolidone, 2-ethylhexyl acrylate, β-hydroxy acrylate, and tetrahydrofurfuryl acrylate.

  Examples of the photopolymerization initiator (S1) include hydroxybenzoyl compounds (2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, benzoin alkyl ether, etc.), benzoyl Formate compounds (such as methylbenzoylformate), thioxanthone compounds (such as isopropylthioxanthone), benzophenones (such as benzophenone), phosphate compounds (1,3,5-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-) Trimethylbenzoyl) -phenylphosphine oxide and the like, and benzyldimethyl ketal and the like. Among these, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone and bis (2,4) are preferable from the viewpoint of preventing coloring of the light transmitting portions 12, 12,. , 6-trimethylbenzoyl) -phenylphosphine oxide. In addition, it is preferable that the said photoinitiator (S1) is contained 0.5 mass% or more and 5.0 mass% or less on the basis (100 mass%) of light transmission part structure composition whole quantity.

  These photocurable prepolymer (P1), reactive diluent monomer (M1) and photopolymerization initiator (S1) can be used alone or in combination of two or more.

  In addition, in the light transmitting part constituting composition, if necessary, silicone additives, rheology control agents, It is also possible to add a defoaming agent, a release agent, an antistatic agent, an ultraviolet absorber and the like.

  Next, the light absorption parts 13, 13,. The light absorbing portions 13, 13,... Are elements disposed between the light transmitting portions 12, 12,... And having a substantially trapezoidal surface in the cross section shown in FIGS. An upper base and a lower base longer than the upper base in the substantially trapezoidal cross section are arranged in a direction along the film surface of the louver film 11. In addition, a surface corresponding to the lower base of the substantially trapezoidal cross section is arranged in parallel between the upper bases of the light transmitting portions 12, 12,. In addition, one surface of the louver film 11 is formed by the lower bottom of the light absorbing portions 13, 13,... And the upper bottom of the light transmitting portions 12, 12,. It is preferable that the hypotenuse in the substantially trapezoidal cross section forms an angle of 0 degree or more and 10 degrees or less with respect to the normal direction of the film surface of the louver film 11. When the angle of the hypotenuse is close to 0 degrees, the cross section is substantially rectangular. In addition, the slope of the oblique side of the light absorbing portions 13, 13,... Does not necessarily have to be constant, and may be a polygonal line or a curved line. Further, the light absorbing portions 13, 13,... May have a substantially triangular cross section.

  .. Are made of a predetermined material having a refractive index Nb that is smaller than the refractive index Np of the light transmitting portions 12, 12,. As described above, by setting the refractive index Np of the light transmitting portions 12, 12... And the refractive index Nb of the light absorbing portions 13, 13,... To Np> Nb, the light source incident on the light transmitting portions 12, 12,. Can be reflected by Snell's law at the interface between the light absorbing parts 13, 13,... And the light transmitting parts 12, 12,. The difference in refractive index between Np and Nb is not particularly limited, but is preferably greater than 0 and 0.06 or less.

  Further, in the present embodiment, the relationship of Np> Nb is preferable as described above, but is not necessarily limited to this, and the refractive index of the light transmission part and the refractive index of the light absorption part may be the same. It is also possible to make the refractive index of the light transmission part smaller than the refractive index of the light absorption part.

  In addition, the light-absorbing part 13, 13,... In this embodiment is a light-absorbing part-constituting composition that includes the light-absorbing particles 14, 14,... And the binder 15 in which the light-absorbing particles 14, 14,. It is configured by filling a groove between the light transmitting portions 12, 12,. As a result, the image light incident on the inner side of the light absorbing portions 13, 13,... Without being reflected by Snell's law at the interface between the light transmitting portions 12, 12,. It can be absorbed by the particles 14, 14,. Furthermore, the external light from the observer side incident at a predetermined angle can be appropriately absorbed by the light absorbing particles 14, 14,..., And the contrast of the image can be improved.

  At this time, the binder 15 is made of the material having the refractive index Nb. Although what is used as the said binder is not specifically limited, What is hardened | cured by light, such as an ultraviolet-ray, is preferable, for example, a reactive dilution monomer (M2) and photopolymerization start to a photocurable prepolymer (P2) A photocurable resin composition containing the agent (S2) is preferably used.

  Examples of the photocurable prepolymer (P2) include urethane (meth) acrylate, polyester (meth) acrylate, epoxy (meth) acrylate, and butadiene (meth) acrylate.

  Examples of the reactive dilution monomer (M2) include monofunctional monomers such as N-vinyl pyrrolidone, N-vinyl caprolactone, vinyl imidazole, vinyl pyridine, styrene, and other vinyl monomers, lauryl (meth) acrylate, stearyl ( (Meth) acrylate, butoxyethyl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, methoxydipropylene glycol (meth) acrylate, paracumylphenoxyethyl (meth) ) Acrylate, nonylphenoxy polyethylene glycol (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, isobornyl (meth) a (Meth) acrylic acid ester monomers such as relate, cyclohexyl (meth) acrylate, benzyl methacrylate, N, N-dimethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylate, acryloylmorpholine, A (meth) acrylamide derivative is mentioned. Polyfunctional monomers include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polytetra Methylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 3-methyl-1, 5-pentanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, dimethylol-tricyclodecane di (meth) acrylate, hydroxypivalate neopentyl glycol di (meth) acrylate Bisphenol A polypropoxydiol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, ethoxylated trimethylolpropane tri (meth) acrylate, propoxylated trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) Acrylate, glyceryl tri (meth) acrylate, propoxylated glyceryl tri (meth) acrylate, tris (2-hydroxyethyl) isocyanurate triacrylate, pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate And dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and the like.

  Examples of the photopolymerization initiator (S2) include 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2,2-dimethoxy-1,2-diphenylethane- Examples include 1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide. Among these, the irradiation device for curing the photocurable resin composition and the curability of the photocurable resin composition can be arbitrarily selected. The amount of the photopolymerization initiator (S2) contained in the photocurable resin composition is based on the total amount of the photocurable resin composition (100% by mass) from the viewpoint of curability and cost of the photocurable resin composition. 0.5 mass% or more and 10.0 mass% or less is preferable.

  These photocurable prepolymer (P2), reactive diluent monomer (M2) and photopolymerization initiator (S2) can be used alone or in combination of two or more.

  Specifically, refraction of polymerizable components (specifically, photocurable prepolymer (P2) and reactive dilution monomer (M2)) composed of urethane acrylate, epoxy acrylate, tripropylene glycol diacrylate and methoxytriethylene glycol acrylate. The ratio, viscosity, or influence on the performance of the louver film 11 is taken into consideration and used.

  Moreover, you may add a silicone, an antifoamer, a leveling agent, a solvent, etc. to a light absorption part structure composition as an additive as needed.

  The light-absorbing particles 14, 14,... Are contained in the light-absorbing part constituting composition, and act to absorb stray light and external light when the light-absorbing parts 13, 13,.

As the light-absorbing particles 14, 14,..., Light-absorbing colored particles such as carbon black are preferably used. However, the present invention is not limited to these, and a specific wavelength is selectively selected according to the characteristics of the image light. Absorbing colored particles may be used. Specific examples include organic fine particles colored with metal salts such as carbon black, graphite, and black iron oxide, dyes, pigments, colored glass beads, and the like. In particular, colored organic fine particles are preferably used from the viewpoints of cost, quality, availability, and the like. More specifically, acrylic cross-linked fine particles containing carbon black, urethane cross-linked fine particles containing carbon black, and the like are preferably used. Such colored particles are usually contained in the light absorbing part constituting composition in a range of 3% by mass to 30% by mass. The average particle diameter of the colored particles is preferably 1.0 μm or more and 20 μm or less. When forming the light absorbing portions 13, 13,..., As will be described later, while filling the grooves between the light transmitting portions 12, 12,. A step of scraping off an excess of the light absorbing portion constituting composition using a blade is included. At this time, by using colored particles having an average particle diameter of 1.0 μm or more, it is possible to prevent the colored particles from easily passing through the gap between the doctor blade and the light transmitting parts 12, 12,. It is possible to prevent the colored particles from remaining on 12, 12,.

  Also, depending on the material constituting the light transmission part, the surface of the light absorption part may be filled on the same plane (smooth) with respect to the surface of the light transmission part, or may be filled in a concave shape. is there.

  The means for absorbing light is not limited to the method using light absorbing particles as in this embodiment. Other examples include coloring the entire light absorbing portion with a pigment or dye.

  The light absorbing portions 13, 13,... Can be formed using the above-described light absorbing portion constituting composition as described in detail later.

<Method for producing louver film>
FIG. 3 is a flowchart of a method for producing a louver film according to one embodiment. Drawing 4 is a key map explaining the manufacturing method of the louver film concerning one form. FIG. 5 is a conceptual diagram for explaining the light transmitting portion forming step. FIG. 6 is a conceptual diagram illustrating the light absorbing portion forming step. Hereinafter, the manufacturing method of the louver film will be described with reference to FIGS. 1 to 6 by taking the manufacturing method of the louver film 11 shown in FIGS. 1 and 2 as an example.

  The method of manufacturing the louver film of this example is arranged in parallel so that light can be absorbed between the light transmission parts 12, 12,... Arranged in parallel along the film surface so that light can be transmitted. It is a method of manufacturing the louver film 11 provided with the light absorption parts 13, 13,. Specifically, a light transmitting portion forming step S2 (hereinafter, simply referred to as “step S2”) for forming the light transmitting portions 12, 12,... On the substrate 10, and the light transmitting portion 12, The louver film 11 is formed on the base material 10 through a light absorbing portion forming step S3 (hereinafter sometimes simply referred to as “step S3”) in which the light absorbing portions 13, 13,. A step of forming, and a peeling step S4 for peeling the base material 10 and the louver film 11 (hereinafter may be simply referred to as “step S4”). Further, a release layer forming step S1 (in which a release layer 18 that facilitates peeling off the base material 10 and the louver film 11 in step S4 is applied to the surface of the base material 10 on the side where the louver film 11 is formed). Hereinafter, it may be simply referred to as “step S1”. Hereinafter, these steps will be described.

(Peeling layer forming step S1)
Step S1 is a step in which a release layer 18 that facilitates peeling off the base material 10 and the louver film 11 in step S4 is applied to the surface of the base material 10 on the side where the louver film 11 is formed.

  In the conventional method for producing a louver film, since the rigidity of the louver film alone is weak, a base material is used for the purpose of reinforcement. By forming a louver film on the base material, the strength of the louver film at the time of production or the like was ensured. In particular, when a louver film is produced using an ultraviolet curable resin, a substrate is essential. Furthermore, the louver film manufactured by the conventional method for manufacturing a louver film is provided with a base material even after being incorporated in a display device or the like, so that the louver film and the base material are not separated. It was glued.

  On the other hand, in the manufacturing method of the louver film of this example, the base material 10 and the louver film 11 are separated in step S4. Therefore, it is preferable to provide the release layer 18 in step S1. The release layer 18 is a layer intended to temporarily bond the base material 10 and the louver film 11 at the time of manufacturing the louver film 11, and the adhesive force is later applied to the base material 10 and the louver film in step S <b> 4. 11 must be peeled off. However, the adhesive strength of the release layer 18 needs to have an adhesive strength that does not separate the base material 10 and the louver film 11 in step S2 and the like. That is, as will be described later, when the step S2 is a step of forming the light transmitting portions 12, 12,... Using the mold roll 32 having a groove corresponding to the shape of the light transmitting portions 12, 12,. The release layer 18 needs to have an adhesive force for adhering the base material 10 and the louver film 11 with an adhesive force stronger than that required to peel off the mold roll 32 and the light transmitting parts 12, 12,... In step S2. There is.

  As a material constituting the peeling layer 18 as described above, a known adhesive resin capable of adjusting the adhesive force can be used. As the adhesive resin, for example, a mixed resin containing an acrylic resin and a melamine resin at a predetermined ratio can be used. In the mixed resin, the mixing ratio of the acrylic resin and the melamine resin is preferably 10 parts by mass or more and 90 parts by mass or less, and 10 parts by mass or more and 90 parts by mass or less of the melamine resin. In the mixed resin, when the amount of the acrylic resin is increased, the adhesive force is increased, and when the amount of the melamine resin is increased, the adhesive force is decreased. Examples of the acrylic resin contained in the mixed resin include acrylic resins obtained by copolymerizing a functional monomer. As the acrylic resin, for example, there are products such as DYNAR HR606 manufactured by Mitsubishi Rayon Co., Ltd., Cotax SA107-302 manufactured by Toray Industries, Inc., and ACRYDEC A405-409 manufactured by DIC Corporation. Examples of the melamine resin included in the mixed resin include butanol-modified or methanol-modified melamine resin. Examples of the butylated melamine resin include Uban 20SB manufactured by MT Aqua Polymer Co., Ltd. and Melan 24 manufactured by Hitachi Chemical Co., Ltd., and examples of the methylated melamine resin include those manufactured by MT Aqua Polymer Co., Ltd. There are Cymel 325 and L-105-60 manufactured by DIC Corporation. The method for forming the release layer 18 using such a mixed resin is not particularly limited. For example, a method of forming the release layer 18 made of the mixed resin by applying the mixed resin using a gravure coater and drying it can be considered.

  Note that the release layer 18 does not have to be formed on the entire surface of the substrate 10 on the side where the louver film 11 is formed, and may be formed within a range in which the above purpose of forming the release layer 18 can be achieved.

  Further, in the louver film manufacturing method of this example, step S1 is not essential, and in step S4, the substrate 10 and the louver film 11 can be peeled off by heating, humidification, or the like.

(Light transmission part formation process S2)
Step S2 is a step of forming the light transmitting portions 12, 12,... On the base material 10, as shown in FIG. 4A shows an example in which the light transmitting portions 12, 12,... Are formed on the base material 10 via the release layer 18, but as described above, the release layer 18 is not essential. Absent.

  The light transmitting portions 12, 12,... Can be formed by using, for example, the apparatus shown in FIG. That is, in order to form the light transmitting portions 12, 12,..., First, a mold roll 32 having grooves having a shape corresponding to the shape of the light transmitting portions 12, 12,. Next, the base material 10 is fed between the mold roll 32 and the nip roll 31. An arrow x shown in FIG. 5 is a direction in which the substrate 10 is fed. In accordance with the feeding of the base material 10, the droplets of the light transmitting portion constituting composition 36 are continuously supplied between the mold roll 32 and the base material 10 by the supply device 35. When the light transmitting portion constituting composition 36 is supplied from the supply device 35 onto the base material 10, a bank in which the light transmitting portion constituting composition 36 is accumulated is formed between the mold roll 32 and the base material 10. To. In this bank, the light transmitting portion constituting composition 36 spreads in the width direction of the base material 10.

  The light transmitting part constituting composition 36 supplied between the mold roll 32 and the base material 10 as described above is caused by the pressing force between the mold roll 32 and the nip roll 31 and the base material 10 and the mold roll 32. It is filled between. Thereafter, the light transmitting portion constituting composition 36 on the substrate 10 is irradiated with ultraviolet rays or the like by the irradiation device 34 to cure the light transmitting portion constituting composition 36, thereby forming the light transmitting portions 12, 12,. it can. After the light transmitting portions 12, 12,... Are formed, the sheet on which the light transmitting portions 12, 12,... Are formed on the substrate 10 is pulled from the mold roll 32 by being pulled through the peeling roll 33. Torn off.

  In addition, it is preferable that the base material 10 is comprised with the material which has a polyethylene terephthalate (PET) as a main component. When the base material 10 has PET as a main component, the base material 10 may include other resins. Various additives may be added as appropriate. Examples of general additives include phenol-based antioxidants, lactone-based stabilizers, and the like. Here, “main component” means that the PET is contained in an amount of 50% by mass or more with respect to the entire material forming the base material layer (hereinafter the same).

However, the main component of the material constituting the substrate 10 is not necessarily PET, and may be other materials. Examples thereof include polybutylene terephthalate, polyethylene naphthalate, terephthalic acid-isophthalic acid-ethylene glycol copolymer, polyester resins such as terephthalic acid-cyclohexanedimethanol-ethylene glycol copolymer, and polyamide resins such as nylon 6. , Polyolefin resins such as polypropylene and polymethylpentene, acrylic resins such as polymethyl methacrylate, styrene resins such as polystyrene and styrene-acrylonitrile copolymer, cellulose resins such as triacetyl cellulose, imide resins and polycarbonate resins Etc. Moreover, you may add additives, such as a ultraviolet absorber, a filler, a plasticizer, an antistatic agent, in these resins suitably as needed.
In addition to performance, from the viewpoints of mass productivity, price, availability, etc., it is preferable that the base material 10 is made of a resin mainly composed of PET.

(Light absorption part formation process S3)
Step S3 is a step of forming light absorbing portions 13, 13,... Between the light transmitting portions 12, 12,... Formed on the base material 10 in Step S2, as shown in FIG. .. Can be formed by using the apparatus shown in FIG. That is, as shown in FIG. 6, first, the light absorbing portion constituting composition 38 is supplied onto the light transmitting portions 12, 12,... Of the sheet on which the light transmitting portions 12, 12,. Then, the light absorbing portion constituting composition 38 is filled in the grooves 13 ′, 13 ′,... Between the light transmitting portions 12, 12,. At this time, the doctor blade 37 fills the grooves 13 ′, 13 ′,... Between the light transmitting portions 12, 12,. Drop it. Thereafter, the light absorbing portion constituting composition 38 remaining in the grooves 13 ′, 13 ′,... Between the light transmitting portions 12, 12,. Light absorbing portions 13, 13,... Can be formed between them. 6 is the sheet feeding direction in which the light transmission parts 12, 12,... Are formed on the base material 10.

  At this time, the elastic modulus of the light transmitting portions 12, 12,... Is preferably 10 MPa or more and less than 2000 MPa. When the elastic modulus of the light transmitting parts 12, 12,... Is 2000 MPa or more, it becomes hard and a problem of cracking or chipping occurs, or when the light absorbing parts 13, 13,. There exists a possibility that the external appearance defect may arise on the surface of the film 11, or the transmittance | permeability of the louver film 11 may fall. That is, when the light transmitting parts 12, 12,... Are too hard, when the doctor blade 37 scrapes off the surplus portion of the light absorbing part constituting composition 38 supplied onto the light transmitting parts 12, 12,. Is not deformed even if it is pressed against the light transmitting parts 12, 12,..., There is a possibility that the excess light absorbing part constituting composition 38 cannot be scraped off. When the elastic modulus of the light transmitting parts 12, 12,... Is in the above range, when the doctor blade 37 is pressed, the excess light absorbing part constituting composition 38 is scraped off by deformation of the light transmitting parts 12, 12,. Defects can be eliminated, and appearance defects can be prevented from occurring on the surface of the louver film 11, and the transmittance of the louver film 11 can be prevented from being lowered. When the elastic modulus of the light transmission parts 12, 12,... Is 10 MPa or less, the light transmission parts 12, 12,... Are too soft. It becomes difficult to release from the roll 32.

(Peeling step S4)
Step S4 is a step of peeling the base material 10 and the louver film 11 from the sheet on which the louver film 11 is formed on the base material 10 through the steps S2 and S3. As a method of peeling off the base material 10 and the louver film 11, for example, the following methods can be considered. First, at the end of the sheet on which the louver film 11 is formed on the base material 10, the tip of a sharp object such as a cutter knife is inserted into the interface between the base material 10 and the louver film 11. The film 11 is peeled off. At this time, if the sheet is held in a moist heat environment in advance, the substrate 10 and the louver film 11 can be easily separated. If the base material 10 and the louver film 11 are peeled at the end portion of the sheet, the peeling between the base material 10 and the louver film 11 can be advanced with a weak force. After the peeling of the base material 10 and the louver film 11 is progressed in the entire width direction of the sheet, the base material 10 and the louver film 11 can be easily peeled by rolling the louver film 11 around a columnar body or the like. .

  Thus, according to the manufacturing method of the louver film of this example, by removing the base material that does not contribute to the optical performance, it is possible to obtain a louver film that is reduced in weight and thickness while maintaining the function as the louver film. Can do. On the other hand, in order to produce a louver film stably, it is necessary to give a certain amount of strength at the time of manufacture, and the role that the base material should play from this viewpoint is large. According to the manufacturing method of the louver film of this example, since the base material is used when manufacturing the louver film, the louver film can be stably produced.

  The louver film manufactured by the manufacturing method of this example can be used for a display device including various display devices such as a liquid crystal panel and an electroluminescence (EL) panel. Below, the example which used the louver film manufactured by the manufacturing method of this example for a liquid crystal panel is demonstrated.

<LCD panel>
Next, a liquid crystal panel according to one example will be described. FIG. 7 is a cross-sectional view schematically showing the configuration of a part of a display device including the liquid crystal panel 4 according to one embodiment. In FIG. 7, the right side of the drawing is the observer side.

  The liquid crystal panel 4 shown in FIG. 7 is a liquid crystal panel including two polarizing plates 41 and 45 and a liquid crystal layer 43 disposed between the two polarizing plates 41 and 45. Further, of the two polarizing plates 41 and 45, the pressure-sensitive adhesive layer 48 is interposed on the viewer-side surface of the polarizing plate 45 that becomes the viewer side when the liquid crystal panel 4 is incorporated in a display device. While the louver film 11 is bonded, the louver film 11 is the outermost layer of the liquid crystal panel 4. The configuration of the liquid crystal panel 4 will be described in more detail. The liquid crystal layer 44 is sandwiched between the TFT substrate 42 and the CF substrate 44, and the polarizing plate 41 is bonded to the TFT substrate 42 via an adhesive layer 46. The polarizing plate 45 is bonded to the CF substrate 44 through the adhesive layer 47. Hereinafter, these elements constituting the liquid crystal panel 4 will be described.

  The louver film 11 is manufactured by the above-described louver film manufacturing method, and the light transmission parts 12, 12,... Arranged in parallel along the film surface so as to transmit light, and the light transmission parts 12, 12 ,... Are disposed in parallel so as to be able to absorb light. In the cross section in the thickness direction of the louver film 11, the cross-sectional shape of the light absorbing portions 13, 13,... Is a substantially trapezoid having an upper base and a lower base longer than the upper base. Further, the louver film 11 is arranged so that the bottom of the substantially trapezoidal cross section of the light absorbing portions 13, 13,...

  Since the louver film 11 does not have the base material provided in the conventional louver film, the liquid crystal panel 4 is provided with the louver film 11, and the liquid crystal panel 4 can be reduced in weight and thickness. There is no particular limitation on the device on which the liquid crystal panel can be mounted, but it is preferably used for a portable terminal such as a mobile phone in which weight reduction and thinning are important from the viewpoint that weight reduction and thinning are possible. it can.

  Further, since the louver film 11 has no base material, when the liquid crystal panel 4 is provided in a display device, the reflection surface of external light is reduced by one. That is, conventionally, the interface between the louver film and the base material has been a reflection surface for external light. However, since the louver film 11 has no base material, the reflection surface can be eliminated. By reducing the reflection surface of the external light, the contrast of the image light can be improved.

  Conventionally, after installing a liquid crystal panel in a display device, a louver film is usually bonded to the display surface of the display device. That is, the distance between the liquid crystal layer and the louver film is large, and the louver film is provided at a position away from the region where the image light is imaged. In such a case, a so-called ghost may occur due to reflection of image light or the like. On the other hand, according to the liquid crystal panel 4, since the louver film is provided in the liquid crystal panel, the light source and the louver film are close to each other, and ghosting can be suppressed.

  In addition, since the liquid crystal panel 4 includes the louver film 11, the louver film is conventionally pasted on the display surface of the display device after the liquid crystal panel is installed on the display device. it can.

  Further, as will be described below, the louver film 11 can prevent so-called peeping by condensing video light incident from the light source side. Furthermore, by condensing the image light, the displayed image can be recognized even if the light emitted from the light source is weakened, so that power consumption can be suppressed. Furthermore, the visibility in the outdoors can be improved.

  FIG. 8 is a conceptual diagram showing an example of an optical path of light incident on the louver film 11 in the liquid crystal panel 4 shown in FIG.

  The video light L11 incident on the louver film 11 from the light source 1 side passes through the louver film 11 and is normally emitted to the viewer side. Further, as described above, by providing a difference in refractive index between the light transmitting parts 12, 12,... And the light absorbing parts 13, 13,..., The video lights L12, L13 are transmitted through the light transmitting parts 12, 12,. Reflected at the interface with the absorbers 13, 13,... At this time, by tilting the oblique sides of the light absorbing portions 13, 13,... As described above, the angle of light changes before and after reflection by the oblique sides, and the image light is condensed in the front direction of the display surface of the display device. be able to.

  Further, the image light L15 is not reflected at the interface based on the refractive index difference between the light transmitting parts 12, 12,... And the light absorbing parts 13, 13,. The video light that has entered. Such image light L15 is absorbed by the light absorbing particles. Also, stray light can be absorbed in this manner. On the other hand, external light L14 incident on the louver film 11 from the observer side as external light is incident on the light absorbing portion 13 and absorbed by the light absorbing particles 14. In this way, a part of the external light is absorbed by the light absorbing portions 13, 13,... And the contrast can be improved.

  Returning to FIG. 7, the adhesive layers 46, 47 and 48 will be described. The pressure-sensitive adhesive layers 46, 47 and 48 are layers containing a pressure-sensitive adhesive. As the pressure-sensitive adhesive used for the pressure-sensitive adhesive layers 46, 47, and 48, known pressure-sensitive adhesive materials and adhesives can be used, which are optically transparent and free from peeling and significant discoloration under the use environment. It should be non-damaging.

  The polarizing plates 41 and 45 are a pair of optical elements disposed so as to sandwich the liquid crystal layer 44, and absorb polarized light having a vibration plane parallel to the absorption axis direction, and have a vibration plane orthogonal to the absorption axis direction. It has a function of transmitting polarized light. As such polarizing plates 41 and 45, those provided in a normal liquid crystal panel can be used.

  On the TFT substrate 42, active elements such as TFTs and electrodes to be sub-pixels are arranged on the liquid crystal layer 43 side. The CF substrate 44 has a color filter such as black matrix (BM), R (red), G (green), and B (blue) arranged on the liquid crystal layer 43 side, and is called a common electrode or a common electrode made of transparent electrodes. Is made on the entire surface of the substrate. The liquid crystal layer 43 displays video information to be emitted here. As the TFT substrate 42, the liquid crystal layer 43, and the CF substrate 44, those provided in a normal liquid crystal panel can be used.

  The liquid crystal panel 4 can be used by being incorporated in a display device as shown in FIG. The display device shown in FIG. 7 includes a light source 1, a light guide plate 3 having a reflective layer 2, a liquid crystal panel 4 disposed on the viewer side from the light guide plate 3 through the air layer B, and the air layer A through the air layer A. A protective plate 6 disposed on the viewer side from the liquid crystal panel 4 and a functional layer 7 formed on the viewer side of the protective plate 6 are provided.

  As the light source 1, a light source used in a normal liquid crystal display device can be used. FIG. 7 illustrates an example of an edge input type in which the light source 1 is arranged at the edge (edge) and light is finally emitted in a planar shape using the reflective layer 2 or the like. However, the present invention is not limited to such a form, and a form in which the light sources are arranged almost uniformly in the plane to form a planar light source may be used. The light from the light source 1 becomes image light, passes through the liquid crystal panel 4 and the like, and is emitted to the viewer side.

  The reflective layer 2 and the light guide plate 3 are provided for the purpose of emitting light from the light source 1 toward the liquid crystal panel 4. Light from the light source 1 propagates in the light guide plate 3 while being totally reflected, and is emitted from an appropriate place to the liquid crystal panel 4 side. The light guide plate 3 is usually provided with a prism, a lens, an emboss, and the like for controlling light from the light source 1 continuously or randomly on the front surface or the back surface. The reflective layer 2 is provided to reflect the light traveling toward the side opposite to the liquid crystal panel 4 side of the light guide plate 3 to the liquid crystal panel 4 side. As such a reflection layer 2 and the light guide plate 3, those used in a normal liquid crystal display device can be used.

  The protective plate 6 is usually fixed to a housing of the display device or the like, and an air layer A is formed between the liquid crystal panel 4 and the protective plate 6. The liquid crystal panel 4 is disposed such that the louver film 11 is in contact with the air layer A.

  The protection plate 6 has a transparent base material that can transmit image light, and a colored layer (not shown) is usually formed on the peripheral edge of the base material. By providing the protective plate 6, it is possible to protect the surface on the viewer side of the display device. Further, by providing the protective plate 6 with a colored layer, it is possible to prevent members such as terminals and backlights installed in the periphery of the image display area of the display device from being seen from the observer side.

  As a base material used for the protective plate 6, a transparent material having a suitable mechanical strength and a thickness can be used. Specific examples of materials used for the substrate include organic materials such as acrylic resins, styrene resins, acrylonitrile / styrene resins (AS resins), polycarbonate resins, polyester resins, polyolefin resins, glass, ceramics, and the like. And inorganic materials such as The base material may be composed of a single layer, or may be configured by laminating a sheet made of an inorganic material and a sheet made of an organic material.

  As described above, the colored layer provided on the protective plate 6 is a layer arbitrarily provided to improve the design of the display device. The color of the colored layer is not particularly limited, and examples thereof include black, brown, white, amber, red, gold, and silver. Such a colored layer can be formed by a printing method such as silk screen printing, gravure printing, or transfer printing.

  The functional layer 7 can be composed of a single layer or a laminate composed of a plurality of layers. Examples of the layer provided in the functional layer 7 include a hard coat layer. The hard coat layer is arranged on the most observer side of the display device and constitutes the display surface of the display device. Therefore, the hard coat layer is given resistance to scratches caused by contact with the outside. Such a hard coat layer can be formed, for example, by curing a photocurable resin. Specific examples of the photocurable resin include acrylic urethane type photocurable resins. Moreover, since the hard-coat layer comprises the display surface of a display apparatus, it is preferable that it has an anti-glare function depending on the case. According to the hard coat layer having the anti-glare function, reflection of external light on the display surface of the display device and reflection of an external image are prevented, and the visibility of the image displayed on the display surface of the display device is improved. be able to. In addition, the layer provided in the functional layer 7 is not limited to a hard coat layer, and can be appropriately provided with what is provided in a conventional display device.

  In the description so far, the louver film 11 is the outermost layer of the liquid crystal panel 4 and the one surface is exemplified and described as being bonded to the polarizing plate 45 through the adhesive layer 48. The liquid crystal panel is not limited to such a form. The louver film can be appropriately disposed between other layers constituting the liquid crystal panel. For example, in the case of the layer structure as shown in FIG. 7, a louver is provided between the CF substrate 44 and the polarizing plate 45, between the TFT substrate 42 and the polarizing plate 41, the surface of the polarizing plate 41 on the light guide plate 3 side, and the like. A film 11 can be placed. Moreover, although the description so far demonstrated the form with which the liquid crystal panel was provided with the louver film manufactured with the manufacturing method of this example, a display apparatus is not limited to this form. For example, the louver film may be bonded to a protective plate or the like. Furthermore, the direction in which the louver film is arranged may be opposite to the illustrated direction, depending on the application.

  A reference example will be described below.

(Reference Example 1)
Louver films having the dimensions shown in Table 1 were produced. Specifically, it is as follows. The dimensions shown in Table 1 correspond to the characters shown in FIG.

Mold rolls were prepared so that the dimensions shown in FIG. 1 would be the dimensions shown in Table 1, respectively. A base material (A4300, manufactured by Toyobo Co., Ltd.) was fed between the mold roll and the nip roll. In accordance with the feeding of the base material, the light transmitting portion constituting composition is supplied between the mold roll and the base material, and the light transmitting portion constituting composition is filled in the groove of the mold roll. The light transmitting portion constituting composition was pressed with a roll and a nip roll. Then, the light transmissive part constituent composition was cured by irradiating ultraviolet light of 800 mJ / cm ² from the substrate side with a high pressure mercury lamp to form a light transmissive part.

  Next, the light absorbing portion constituting composition is supplied from the supply device onto the light transmitting portion obtained above, and the light absorbing portion constituting composition is supplied to the groove between the light transmitting portions using a doctor blade, and the surplus Minutes of the light absorption part constituting composition was scraped off. Thereafter, the light absorbing portion constituting composition was cured by irradiating ultraviolet rays from the side opposite to the side on which the substrate was provided, and the light absorbing portion was formed by the cured light absorbing portion constituting composition. As described above, a louver film having a light transmission part and a light absorption part was formed on the substrate.

  Next, with respect to 100 parts by mass of (meth) acrylic resin adhesive (manufactured by Soken Chemical Co., Ltd., SK Dyne 2094), 0.25 parts by mass of curing agent (manufactured by Soken Chemical Co., Ltd., E-5XM), solvent MIBK30. Each part by mass was added and sufficiently dispersed to prepare an adhesive composition. The pressure-sensitive adhesive composition was applied to the surface of the louver film opposite to the base so that the thickness was 25 μm and the width direction was 1370 mm, and dried at 80 ° C. for 3 minutes. After drying, the obtained coating film was further coated with a release-treated PET film (release film, thickness: 38 μm, width 1380 mm).

  After the louver film was formed on the base material as described above, it was left in an atmosphere of 80 ° C. and 90% humidity for 24 hours, and then the base material and the louver film were peeled off. As a result, it was possible to produce a louver film having no base material by peeling off the louver film and the base material.

(Reference Example 2)
A louver film was prepared in the same manner as in Reference Example 1 except that other ultraviolet curable resins were used as the light transmitting part constituting composition and the light absorbing part constituting composition, and the dimensions of the mold roll were changed. The dimensions of the louver film produced in Reference Example 2 are as shown in Table 1. Also in Reference Example 2, a louver film having no substrate could be produced by peeling off the louver film and the substrate.

DESCRIPTION OF SYMBOLS 1 Light source 2 Reflection layer 3 Light guide plate 4 Liquid crystal panel 6 Protection board 7 Functional layer 10 Base material 11 Louver film 12 Light transmission part 13 Light absorption part 13 'Groove 14 Light absorption particle 15 Binder 18 Peeling layer 31 Nip roll 32 Mold roll ( Mold)
33 Peeling Roll 34 Irradiation Device 35 Supply Device 36 Light Transmission Part Composition 37 Doctor Blade 38 Light Absorption Part Composition 41 Polarizing Plate 42 TFT Substrate 43 Liquid Crystal Layer 44 CF Substrate 45 Polarizing Plate 46 Adhesive Layer 47 Adhesive Layer 48 Adhesive layer A Air layer B Air layer

Claims (2)

A display device comprising a light source, a liquid crystal panel provided on the viewer side from the light source,
The liquid crystal panel is
Two polarizing plates,
A liquid crystal layer disposed between the two polarizing plates;
A light transmission part having a trapezoidal cross section arranged in parallel along the film surface so as to transmit light; and a louver film comprising a light absorption part having a trapezoidal cross section arranged in parallel so as to be able to absorb light between the light transmission parts; With
The louver film is disposed on the light source side surface of the polarizing plate among the light source side of the liquid crystal layer without using a base material, and has a long lower bottom in the trapezoidal cross section of the light absorbing portion and the light. A display device in which a short upper base in the trapezoidal cross section of the transmission portion is oriented toward the light source.   A portable terminal comprising the display device according to claim 1.

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